Sizing formulations for polymeric materials

ABSTRACT

THIS INVENTION RELATES TO HEAT AND HUMIDITY RESISTANT SIZING FORMULATIONS FOR POLYOLEFIN YARNS, NCLUDING POLYPROPYLENE, COMPRISING: (A) A MAJOR AMOUNT OF A RESIN COMPONENT SELECTED FROM (1) HYDANTOIN FORMALDEHYDE RESIN, (2) A COPOLYMER OF VINYL PYRROLIDONE AND WATER INSOLUBLE COMMONOMER, (3) A COPOLYMER OF VINYL ACETATE AND WATER INSOLUBLE COMMONOMER, ADMIXED WITH: (B) A MINOR AMOUNT OF A POLYVINYL, CONTAINING MOIETY, E.G. POLYVINVYL ALKYL ETHER.

United States Patent 3,644,591 SIZING FORMULATIONS FOR POLYMERICMATERIALS Harold W. Wolf and Stanley E. Ross, Clifton, N.J., as-

signors to .l. P. Stevens & (30., Inc., New York, NY. No Drawing.Original application Aug. 28, 1967, Ser. No. 663,490, now Patent No.3,502,743. Divided and this application Oct. 20, 1969, Ser. No. 871,329

Int. Cl. C08f 33/08 US. Cl. 260-895 6 Claims ABSTRACT OF THE DISCLOSUREThe present application is a division of application Ser. No. 663,490,filed Aug. 28, 1967, now US. Pat. 3,502,743.

This invention relates to sizing formulations useful for protectingyarns derived from thermoplastic materials.

More particularly, this invention concerns sizing formulations useful inprotecting polyolefin yarns such as polypropylene during processing.

Sizing materials are customarily applied to most yarns to minimizebreakage due to abrasion, friction and related causes which occur duringweaving.

A great many sizing formulations are known and a considerable number offormulations are sold commercially. The formulations vary from simplestarches and waxes to complex formulations containing severalcomponents. For most purposes satisfactory protection can be afforded toglass and polymerically derived yarns using one or more of the knownformulations. However, because of their chemical inertness and somewhatunique physical properties, attempts to utilize known sizingformulations for polyolefin yarns such as those derived frompolypropylene, polyethylene, and poly (4-methyl-pentene-1) have beenunsuccessful. Particularly troublesome are the fine denier, continuousfilament yarns as Well as spun yarns produced from staple fibers. Forexample, in many instances the sizes have little initial afiinity forpolyolefins or once applied are either shed during processing or elseaccumulate to an excessive degree as a tacky coating. In the latterinstance, the tacky material adheres to the metal surfaces encounteredduring weaving and results in more damage to the treated yarn thannormally occurs in processing untreated (control) yarns.

In addition to the minimal requirement of affording prophylacticlubrication to the yarn, a size for polyolefins as illustrated bypolypropylene must meet more stringent requirements. They are asfollows:

1) Ease of preparation.To be useful, the size must lend itself toconventional, simple cooking and handling procedures practiced in sizerooms by relatively non-technically trained personnel;

(2) Affinity for polypropylene and compatibility with producers spinfinishes.Not only must the size have an affinity per se, but the sizemust be compatible with the diversity of finishes previously applied tothe yarn by the producer;

(3) Relative insensitivity toward humidity.-The normal environment ofthe weaving room is one of high 3,644,591 Patented Feb. 22, 1972humidity. The size must be resistant to humidity so that it survives theapplication period and serves its function;

(4) Resistance to heat.-During processing the sized yarn rubs against avariety of metal parts including lease rods, dropwires, heddles and thelike. This abrasion generates considerable heat which can degrade thefinish and reduce its usefulness. For this reason, good heat stabilityis another important quality for the sizing formulation;

(5) Compatibility with finishes. -An effective size must be compatiblewith a vast variety of finishes and industrial coatings, particularly inthe case of water insoluble materials;

(6) Ability to form a protective film or coating.This is especiallysignificant when the size is to be applied to yarns having little or notwist;

(7) Low cost and availability-Since the purpose of the size is tominimize costs of breakage and it is ultimately removed from the fabric,the cost of the size must be minimal to make its use attractive.Further, the components of the size must be readily available tominimize needless changes in processing operations.

As the above discussion suggests, the development of sizes specificallytailored to polypropylene yarns, especially lighter denier yarns andspun yarns, would represent a useful step forward in the polyolefin art.

Therefore, it is an object of this invention, among others, to set forthnovel sizing formulations suitable for polyolefin yarns such aspolypropylene.

Another object of this invention is to disclose size formulationsespecially designed for lighter denier polyolefin yarns derived bothfrom continuous filament and spun yarns.

Yet another more specific object of this invention is to develop lowcost polypropylene sizes resistant to the attack of heat and humiditywhich are compatible with commercially utilized finishes.

Further objects will suggest themselves to those skilled in the artafter a perusal of this application.

The above objects are achieved through the application of the sizingformulations whose compositions (in parts by weight) are given below.

FORMULATION 1 -100 parts by weight of a hydantoin formaldehyde resinadmixed with 0-10 parts by weight of a polyvinyl containing moiety; 1-20parts by weight of a copolymer derived from vinylpyrrolidone and waterinsoluble comonomers, and 0-5 parts by weight of sizing adjuvants.

FORMULATION 2 65-100 parts by weight of a copolymer derived from thegroup consisting of vinylpyrrolidone and vinyl acetate, and waterinsoluble comonomers; 0-35 parts by weight of a polyvinyl containingmoiety, and 0-5 parts by weight of sizing adjuvants.

FORMULATION 3 80-100 parts by weight of a hydantoin formaldehyde resin,admixed with 3-20 parts by weight of a polyvinyl containing moiety.

The above formulations are expressed in the form of their concentratedsolutions and should be diluted with appropriate diluents to aconvenient solids level for utilization as sizing. Ordinarily, thedilution is made to about the 5 to 15% solids level, preferably usingwater or admixtures of water and any other suitable diluent. The latterincludes the lower alkanols such as ethanol and the propanols as well asany other inert diluent.

The sizing formulations may also contain a small quantity of suitablesizing adjuvants such as wetting agents, detergents, surfactants,thickening agents, softening agents, stabilizing agents and the like.The adjuvants are normally used in small amounts, most usuallyconstituting from about 0.1 to by weight of the formulation.

Illustrative adjuvants include wetting agents such as alkyl polyethyleneglycol ethers and alkyl aryl polyethylenes and their salts, includingtridecyl polyethylene glycol ether, dodecyl phenyl polyethylene glycolether, nonyl phenyl polyethylene glycol ether, trimethyl nonylpolyethylene glycol ether, the sodium sulfate derivatives of2-ethyl-l-hexanol, the sodium sulfate derivative of 7-ethyl-2-methyl,4-undecanol, dioctyl sodium sulfosuccinate, nonyl-phenyl-polyethoxyethanol, octyl-phenyl-polyethoxy ethanol, isooctyl-phenyl-polyethoxyethanol, t-isooctyl phenyl(polyoxymethylene) ethanol, tisooctylphenoxyhexadecakis (ethylenoxy) ethanol, stearyl dimethyl benzylammonium chloride, plasticizers such as triacetin and the like.

As indicated above, the use of the various adjuvants is not critical tothe success of the sizing formulations and for this reason no attempt ismade herein to compile a lengthy list of utilizable materials. However,a satisfactory, but not exhaustive list of these adjuvants appears amongother places in Soap and Chemical Specialties, vol. 31, No. 7, page 61;No. 8, pages 48-61; No. 9, pages 52-67 and No. 10, pages 38-67 (1955),as well as the more recent editions and revisions of these listings.

The sizing formulations of this invention may be applied topolypropylene yarns using a variety of procedures and equipment wellknown in the textile art. One suitable procedure among many otherscomprises passing a plurality of polypropylene yarn ends from a creel toa beam through a size box which contains the sizing formulation so thatthe sizing composition is deposited therein.

The temperature of the size bath is not critical and can range ratherbroadly between about 70 F. and 200 F., more preferably between about130-150 F. The residence time in the bath is not important as long as atleast the desired amount or more of size is applied. A convenient meansof assuring this is by regulating the speed of the yarn fed into thesize box and/or by adjusting the concentration of the size. For theinstant invention a rate of feed ranging between 10-25 yards a minutehas been found to be satisfactory when the size concentration variesbetween the aforementioned 5l5% solids level.

After application of the size to the yarn, excess size is removed fromthe treated yarn by passing the yarn between one or more sets of squeezerolls set to retain the desired degree of pickup. Ordinarily, thepressure of the rolls is adjusted to obtain a pickup of between 50- 100%based on the weight of the untreated yarn.

After this, the treated yarn is substantially dried using conventionaldrying devices such as drying cans or cylinders, hot air, infrared orthe like. Usually, the drying step, whatever the means employed iscarried out between about ISO-230 F. for a sufiicient time to leaveabout 2 to moisture in the sized yarn.

To more clearly indicate the scope of this invention, insofar as thecomponents of the size formulation are concerned, the following glossaryis submitted:

(a) Hydantoin formaldehyde resins.These are resins that are illustratedby the resins selected from the group consisting of dialkyl hydantoinformaldehyde adducts such as dimethyl-, diethy1-, and dibutyl hydantoinformaldehyde resins and methylol dialkyl hydantoins such as monomethyloldimethyl hydantoin, monomethylol diethyl hydantoin as well as theclosely related dimethylol adducts; the preferred resins are thedimethyl hydantoin resins,

(b) Composition containing a polyvinyl moiety. These compositionscomprise polyvinyl alkyl ethers such as the preferred polyvinyl methylether, polyvinyl ethyl ether, the polyvinyl butyl ethers and the like,and

(c) Copolymer derived from the group consisting of vinyl pyrrolidone andvinyl acetate, and water insoluble comonomers.These copolymers resultfrom the combination of varying ratios of vinyl pyrrolidone (from about20 to about parts by weight of vinyl pyrrolidone) and a water insolublemonomer (from about 20 to about 80 parts by weight of monomer) such as2-ethyl hexylacrylate, ethyl acrylate, styrene, vinyl acetate, dibutylmaleate and mixtures thereof. The preferred copolymers are thosecomprising from about 60-80 parts by weight of vinyl pyrrolidone andfrom about 40-20 parts by weight of a monomer selected from the group ofethyl acrylate 2-ethyl hexylacrylate and vinyl acetate.

To best illustrate this invention in its preferred embodiments, thefollowing examples are submitted:

EXAMPLE 1 A polypropylene warp consisting of 6320 ends of black 165denier, 20 filament, 3 turns per inch Z yarn is treated with acncentrated size formulation comprising 93 parts by weight of dimethylhydantoin formaldehyde resin (124 parts by weight of a 75 by weightsolution of the resin in water), 7 parts by weight of polyvinyl methylether (14 parts by weight of a 50% by weight solution of the ether inwater) and 0.05 part by weight of a commercially obtained wetting agent(trimethyl nonyl polyethylene glycol ether). The concentrated solutionis diluted with 12 times its volume of water and is applied from sizeboxes at room temperature with the warp running at a speed of 20 yds./min. through a Cocker slasher. The warp is dried with the cylinders atthe following temperatures:

The above size adheres better to the warp yarn than any previouslyevaluated commercially available size for polypropylene and exhibitsbetter performance on the loom.

EXAMPLE 2 A polypropylene warp (Herculon black polypropylene 165 denier,20 filament, 3 turns per inch Z yarn) is treated in a Cocker slasherwith a concentrated sizing formulation comprising 98 parts by weightdimethyl hydantoin formaldeheyde resin (131 parts by weight of a 75% byweight solution of the resin in water), 2 parts by weight of a copolymerof vinyl pyrrolidone and vinyl acetate (made up from 5 parts by weightof a 40% by weight water solution of copolymer) copolymer comprising aweight ratio of 70 parts by weight of vinyl pyrolidone to 30 parts byweight of vinyl acetate and 0.2 part by weight of triacetin plasticizerand 0.02 part by weight of a wetting agent (dioctyl sodiumsulfosuccinate), diluted with 11 times its volume (to about the 9%solids level) of water. The size box temperature in this run is F. andthe drying cylinders are as follows:

he warp speed through the slasher is 18 yd./min. No deposits are presenton rolls, cans or lease rods.

Laboratory evaluation of the force required to bind the yarns together 1(i.e., 2 ply, 165 denier, 3 turns per inch), tested on the Instron at0.5/min. erosshead speed is as follows:

10% size (solids content)binding force 5.8 grams 15% size (solidscontent)binding force 7.9 grams EXAMPLE 3 Polypropylene yarn (165denier, 2 ply, 3 turns per inch) is treated with a concentrated sizingformulation comprising 95 parts by weight of dimethyl hydantoinformaldehyde (127 parts by weight of a 75% by weight solution of theresin in water) and 5 parts by weight of polyvinyl methyl ether (10parts by weight of a 50% by weight solution of the ether in water),diluted to eleven times its volume in water, the solids level beingabout 9% The conditioned yarn is then tested on the Instron TensileTester to obtain the binding force required toseparate the plies of thesized 2 ply yarn. With the cross-head speed of 0.5/

min. the force 1s as follows:

Percent concentra- Binding tion of force, size on yarn grams ample:

A (DMIHF/PVME) 9 4. 4 B (DMHF/PVME) 14 5.1 Control (no size) 0.5-1.0Polyvinyl alcohol, 1 (Elvan 51 9 2.8 Polyvinyl alcohol, 2 14 2. 8

EXAMPLE 4 A 165 denier, 20 filament, 3 turns per inch Z polypropyleneblack yarn consisting of 4712 ends is treated with a concentrated sizingformulation comprising 85 parts by weight of dimethyl hydantoinformaldehyde resin (113 parts by weight of a 75 by weight solution ofthe resin in water), 15 parts by weight of a copolymer of vinylpyrrolidone and 2-ethyl hexylacrylate (made up from 37.5 parts by weightof a 40% water solution of copolymer), comprising a weight ratio of 80parts by weight of vinyl pyrrolidone to 20 parts by weight of 2- ethylhexylacrylate, diluted to 10 times its volume (10% solids content) withwater. Application is made at 140 F. at a speed of 18 yds./min. using aCocker slasher. The warp is run with a slight tension that producedapproxi mately 2.5% stretch. No deposit or foaming is noted duringslashing. Warps feel smooth and flexible.

Using the same yarn procedure, temperatures and dilutions describedabove, two samples of yarn are treated with diluted sizing formulation.In one instance 15 parts by weight of a copolymer of vinyl pyrrolidoneand styrene (60 parts by weight of vinyl pyrrolidone to 40 parts byweight of styrene) is substituted for the vinyl pyrrolidone- 2-ethylhexylacrylate copolymer while in the second instance l parts by weightof a copolymer comprising 50 parts by weight of vinyl pyrrolidone and 50parts by The force required to separate the plies is termed the bindingforce and is indicative of the adhesion of the sizing formulation to theyarn. The binding force is determined on the conditioned sample (65relaltivehumidity, 70 F.) on the Instron Tensile Tester (InstronCorporation, Canton, Mass), by placing the ends into the upper jaw ofthe machine and having a separating pin fastened to the lower jaw. Theyarns are then separated over a length of 5 inches by operating theeross-head at a. speed of 0.5/min. and averaging peaks on the chart toobtain the average binding force.

weight of ethyl acrylate is substituted for the copolymer of Example 4.In both instances smooth, flexible warps are obtained.

EXAMPLE 5 A warp of 50 ends of 165 denier '34 filament 0.5TZ naturalpolypropylene yarn is sized with a size solution comprising an admixtureof 70 parts by weight of a copolymer of vinyl pyrrolidone and vinylacetate 175 parts by weight of a 40% by weight solution of an aqueoussolution of the copolymer), the copolymer comprising a weight ratio of70 parts by weight of vinyl pyrrolidone to 30 parts by weight of vinylacetate, and 30 parts by weight of polyvinyl methyl ether (60 parts byweight of a 50% by weight solution of the ether in water) diluted withabout 19 times its volume with water to give a total solidsconcentration of 5%. Approximately 0.05 part by weight of trimethylnonyl polyethylene glycol ether is added to the mixture.

The size is applied using a Callaway Model 50 slasher, maintaining thesolution of size in the box at room temperature and slashing the warp at20 yds./min. Approximately yds. of warp is slashed. The sized yarn hasthe following tensile properties compared to the control (unsized yarn).

Elongation, percent Breaking strength Tenacity,

Denier Sized Control (unsized) The sized yarn is woven at speed of 170picks per min. using a construction of 45 picks/inch along with anotherwarp section which had been sized with a commercially available size fornylon (polyacrylic acid). Analysis of the sized yarns gives thefollowing size contents:

Percent size content Inventive sizing formulation As received and sizedwith polyacrylic acid 1.7

EXAMPLE 6 A sizing solution comprising 97 parts by weight of dimethylhydantoin formaldehyde resin (129 parts by weight of a 75% by weightaqueous solution) and 3 parts by weight of a copolymer of vinyl acetateand dibutyl maleate (6 parts by weight of a 50% by weight aqueoussolution) is cast as a film on a polyethylene substrate to determine theadhesion of the size to the substrate. This evaluation is carried out inaccordance with ASTM Method D903-49, entitled Peel or Stripping Strengthof Adhesives. The film is smooth and non-tacky and exhibits a peel valueof 1000 grams/ inch.

Another sizing solution comprising 82 parts by weight of dimethylhydantoin formaldehyde resin (109 parts by weight of a 75 by weightaqueous solution) and 18 parts by weight of a copolymer of vinylpyrrolidone and ethyl acrylate (36 parts by weight of a 50% by weightaqueous solution of the copolymer) is cast as a film on a polypropylenesubstrate. The peel value is 960 grams/inch.

In contrast, a commercially available polyacrylic acid size exhibits apeel value from a polypropylene substrate of 137 grams/inch.

EXAMPLE 7 Two denier/34 filament yarns are plied with 3 turns per inchand treated with a l to 10 volume aqueous dilution of a concentratedsizing formulation comprising 97 parts by weight of a copolymer of vinylpyrrolidone and vinyl acetate (made up from 242 parts by weight of a 40%by weight of an aqueous solution of the copolymer) comprising a Weightratio of 70 parts by weight of vinyl pyrrolidone to 30 parts by Weightof vinyl acetate, 3 parts by weight of triacetin [(CH COOH) C H and 0.2part by weight of trimethyl nonyl polyethylene glycol ether. Theapplication of size is made at room temperature. The procedure fordetermining binding force necessary to separate the plies using theInstron tester is described in the earlier examples. The binding forcein this instance is measured and determined at 13.4 grams compared tounsized yarn value at 0.5 gram. A casting of this same combination on apolypropylene substrate is allowed to dry and conditioned at 65% RH. and70 F. and gives a peel value of 635 grams/inch when peeled at the rateof 0.5 inch/min. on the Instron tester. The conditioned material has asmooth, tack-free surface.

As the foregoing examples indicate, numerous changes and modificationscan be made in the components of the inventive size formulations withoutdeparting from the inventive concept. The metes and bounds of thisinvention are best indicated by the claims which follow.

What is claimed is: 1. A sizing formulation for polyolefins comprising(a) a major amount of a copolymer which is a copolymer of vinylpyrrolidone with a comonomer selected from the group consisting of2-ethyl hexylacrylate, ethyl acrylate, styrene, vinyl acetate, dibutylmaleate and mxtures of, (b) a minor amount of a polyvinyl alkyl ether.

2. A sizing formulation as claimed in claim 1 wherein said copolymer isa copolymer of vinyl pyrrolidone and vinyl acetate.

3. A sizing formulation as claimed in claim 1 wherein said polyvinylalkyl ether is selected from the group con sisting of polyvinyl methylether, polyvinyl ethyl ether and polyvinyl butyl ether.

4. A sizing formulation as claimed in claim 1 comprising at least partsby Weight of said copolymer per each 100 parts by weight of solids.

5. A sizing composition as claimed in claim 1 wherein said polyvinylalkyl ether is polyvinyl methyl ether.

6. The formulation of claim 1 wherein the formulation comprises (a)about parts by weight of copolymer derived from vinyl pyrrolidone andvinyl acetate, admixed with (b) about 30 parts by Weight of polyvinylmethyl ether.

References Cited UNITED STATES PATENTS 4/1970 Press 260--857 6/1960Robinson 26045.95

US. Cl. X.R.

l17l38.8 E; 260-294 UA, 29.6 B, 30.8 R, 31.6, 33.2 R, 33.4 R, 33.4 P,32.4, 851, 874,901

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,644,591 a e February 22, 1972 Harold W. Wolf and Stanley E. RossInventor-(s) It is certified that: error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 19, "cncentrated" should read --eoncentrated Column 7,line 30, Claim 1, "mixtures of" should read mixtures thereof, and

Signed and" sealed this llrth day of May 1971 (SEAL) Attest:

EDWARD I '.FLETCIIER,JR. l c. MARSHALL 'DANN, Attesting OfficerCommissioner of Patents FORM Po-1oso (10-69) v USCOMWDC E "-5.GOVERNMENT PRINTING OFFICE i II! -3'33

